Swallow

See also: Swallow (homonymy)

The swallow is a migrating Oiseau familiar which installs its Nid close to the dwellings (traditionally in the barns and cattle sheds). These birds form part about the Passeriformes of which they constitute the family of the Hirundinidae .

The swallow is the subject many songs and proverbs. A film was even entitled “a swallow made spring. ”

Indeed, it symbolizes the arrival of spring traditionally, because its return of wintering in Africa is done as of the first beautiful days, to nest and reproduce in Europe. This return voyage represents a tour which can exceed the 10.000 km, with for only carburizing a few grams of grease. As soon as the small ones are autonomous, they start to prepare the following migration by accumulating the reserves of grease necessary. But before being autonomous, each oisillon seems to be summarized with a nozzle so much this one is open. It waits until his/her parents bring a full beakful of insects to him. To find all this food, the parents traverse on average 300 km per day; and this, during three weeks.

Like the Pigeon and many other migrating, the swallow finds the place where it nested the last year, when it returns from Africa. What perhaps explains why it recolonise only with difficulty the cities from where it disappeared, even when the conditions of pollution or threats for it seem to have decreased.

Its manpower know a very strong regression since the years approximately 1970, which tends to worsen: a fall of 84% over 10 years was indexed for the house martin (source CRBPO, prone to interpretation, because of natural variations of populations existing also, but considered to be alarming by the ornithologists). This regression could be explained by the rarefaction of its single food, the flying insects (see the article Pesticide S, but it is curious to note that cities which resemble each other in for some preserved of the important populations whereas others lost their swallows). The presence of many wooded spaces and water in the cities seem favorable factors.

Species

There exist 89 species of swallows, of which 5 only nest in France:

The swallow is often confused with the trip hammer S which have longer wings and with the form of more marked forgery. The possible cry (strident and powerful whistle) of the trip hammer also makes it possible to differentiate them easily. The tern, the Estorlet, is not same family.

Threats

The swallows are in many countries of the protected spaces, but it seems that like all the insectivorous species, they suffer from the regression or the poisoning of their food by the pesticides. It is probable that they undergo also the effects of urban pollution and it seems that when a species deserted a city, it returns there only with difficulty. It seems that they can also accumulate the pesticides, the heavy metals and other pollutants themselves accumulated by the insects which it consumes. These poisons are in particular stored in its greases, then salted out in the organization at the time of exhausting voyage of migration towards the south, strongly affecting the chances of survival of the bird.

In addition, modern buildings, with often smooth materials (glass, steel, concrete.), are often adapted to the reception of the swallows of chimneys and window, even if architecture HQE, slowly starts to seek to integrate the Biodiversité (Fifteenth target HQE) on and around the frame while managing the constraints related to the wildlife.

The fact that the parents throw over the nest the droppings of their let us oisillons can also locally pose problem (often solved by the installation of a plate under the nest. (ex; photograph opposite)

Lastly, since 2004, the fears caused by the Avian flu encouraged people to destroy nests or broods (it is strictly prohibited, and probably not only useless, the swallows not forming part of the species at the risk (it seems that the trade and the breeding of the poultries and ducks are by far the first source of risk)), but contra-indicated, because by destroying the nests, one supports the Moustique S and the Mouche S which are carrying also dangerous communicable diseases.

The industrial breedings and the treatment Antiparasitaire of the animals deprive also the swallows of many insects which they captured in the meadows or around the cattle sheds, pigsties and stables where the latter were nourished.

See too

Nest of swallow

External bonds

oiseaux.net: The Swallow

swallow|swallow

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